Method of producing a composite material including three-dimensional (3D) graphene

ABSTRACT

A method for continuously producing a composite material is disclosed. In some implementations, the method includes supplying a thermoplastic resin having an initial density, mixing polypropylene-graft-maleic anhydride (PPgMA) formed of a plurality of interconnected PPgMA molecules throughout the thermoplastic resin, distributing a plurality of carbon particles throughout the thermoplastic resin and the plurality of interconnected PPgMA molecules, and forming, by rotational molding, the composite material based on a combination of the thermoplastic resin, the PPgMA, and at least some of the plurality of carbon particles.

TECHNICAL FIELD

This disclosure relates generally to composite materials, and moreparticularly, to composite materials including various loading levels ofresin, maleated copolymer, and 3D graphene to achieve desirablevisco-mechanical properties.

DESCRIPTION OF RELATED ART

Composite materials are produced from two or more constituent materialshaving dissimilar chemical and/or physical properties that may be mergedsuch that the composite material has properties unlike the two or moreconstituent materials. In some instances, the constituent materials mayremain separate and distinct, which may distinguish the compositematerials from other substances, such as mixtures and solid solutions.Within composite materials, polypropylene-organoclay nanocomposites maybe prepared via melt processing using a twin-screw extrusion of threeconstituent materials, such as polypropylene (PP), maleic anhydridemodified polypropylene oligomers (PPgMA), and clays modified byoctadecyl ammonium. In addition, PP and nano-clay may be compatibilizedby varying a percentage of the PPgMA on the nanocomposite and/or adegree of functionalization of the PPgMA. Although some increases inphysical performance (e.g., tensile strength, toughness, etc.) have beenobserved in relation to conventional materials, evaluated compositeshave not included three-dimensional (3D) graphene, which could impartbeneficial properties. Improvements in composite materials aredesirable.

SUMMARY

This Summary is provided to introduce in a simplified form a selectionof concepts that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tolimit the scope of the claimed subject matter.

In some implementations, the method includes supplying a thermoplasticresin having an initial density, mixing polypropylene-graft-maleicanhydride (PPgMA) formed of a plurality of interconnected PPgMAmolecules throughout the thermoplastic resin, distributing a pluralityof carbon particles throughout the thermoplastic resin and the pluralityof interconnected PPgMA molecules, and forming, by rotational molding,the composite material based on a combination of the thermoplasticresin, the PPgMA, and at least some of the plurality of carbonparticles. In various implementations, chemical bonding between carbonatoms provided by at least some of the plurality of carbon particles andtheir respective adjacent interconnected PPgMA molecules is configuredto increase flexural modulus of the composite material while maintaininga final density of the composite material within a tolerance limit of⁺/⁻3% deviation from the initial density of the thermoplastic resin, thetolerance limit based on the pore volume. In some aspects, the compositematerial may be post-processed by injection molding.

In some instances, the method may also include compressing the compositematerial in one or more directions, and forming one or more of a sheetor a plate based on the compression of the composite material. In otherinstances, the method may also include extruding the composite materialthrough a die, and forming an item based on extrusion of the compositematerial. In some other instances, the method may also include dryingthe composite material to produce a dried composite material, insertingthe dried composite material into a mold, and pumping a mixture ofadditional resin and a catalyst into the mold.

The method may include post-processing the composite material using aresin-transfer molding technique including drying the composite materialto produce a dried composite material. The method may progress withinserting the dried composite material into a mold. The method mayprogress with pumping a mixture of additional resin and a catalyst intothe mold. The method may include post-processing the composite materialusing a reaction injection molding technique including inserting astream of the composite material into a mold. The method may progresswith inserting a stream of linear low-density polyethylene (LLDPE) intothe mold. The method may progress with inserting a catalyst into themold. The method may progress with mixing the composite material, thethermoplastic resin, and the catalyst within the mold.

The method may include post-processing the composite material using avacuum-assisted resin transfer molding (VARTM) technique includingdrawing the composite material into a mold using a vacuum. The methodmay include post-processing the composite material using a filamentwinding fabrication technique including extruding the composite materialthrough a cylindrical mold to produce a composite wire. The method mayprogress with winding the composite wire along an axis to produce afilament-wound composite. The method may include post-processing thecomposite material using a pultrusion technique including generating asemi-molten composite wire by passing a wire of the composite materialthrough a bath maintained at above 22° C. The method may progress withforming an item by passing the semi-molten composite wire through one ormore guides. The method may include post-processing the compositematerial using tube rolling including cutting the composite materialinto one or more predefined patterns. The method may progress withlaying the one or more predefined patterns on a surface. The method mayprogress with rolling over the one or more predefined patterns on thesurface with a mandrel.

The method may include post-processing the composite material usingcompression molding including forming a sheet of the composite material.The method may progress with pouring sliced fiberglass on top of thesheet of the composite material and covering the sheet of the compositematerial and the sliced fiberglass with an additional layer of thecomposite material. The method may include post-processing the compositematerial using injection molding including injecting the compositematerial in a molten state into a mold. The method may progress withextracting a formed product from the mold by cooling the compositematerial within the mold. The method may include molding the compositematerial into one or more shapes using one of vacuum compressionmolding, rotational molding, blow molding, or injection over-molding.

Details of one or more implementations of the subject matter describedin this disclosure are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims. Note thatthe relative dimensions of the following figures may not be drawn toscale.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows micrographs of example composite materials, according tosome implementations.

FIG. 2 shows a micrograph of graphene materials produced by sulfuricacid (H₂SO₄) exfoliation from graphite, according to someimplementations.

FIG. 3 shows micrographs of microwave-energy based wavy and/or wrinkledgraphene, according to some implementations.

FIG. 4 shows a micrograph of example carbon particles, according to someimplementations.

FIG. 5A shows a diagram of an example carbon particle, according to someimplementations.

FIG. 5B shows an example step function representative of the examplecarbon particle of FIG. 5A, according to some implementations.

FIG. 6 shows a graph depicting an example distribution of pore volumeversus pore width of an example carbon particle, according to someimplementations.

FIG. 7A shows a micrograph of example carbon particles, aggregates,and/or agglomerates, according to some implementations.

FIG. 7B shows a micrograph of example carbon particles, aggregates,and/or agglomerates, according to some implementations.

FIG. 8 shows a graph depicting cumulative pore volume versus pore widthfor micropores and mesopores dispersed throughout example carbonparticles, according to some implementations.

FIG. 9 shows an example configuration of example carbon particles,according to some implementations.

FIG. 10 shows a diagram of the chemical structure ofpolypropylene-graft-maleic anhydride (PPgMA), according to someimplementations.

FIG. 11 shows an example chemical reaction mechanism for producing PPgMAand for ozone-treating graphene surfaces, according to someimplementations.

FIG. 12 shows a graph depicting intensity (relative absorbance) perwavenumber (cm⁻¹), according to some implementations.

FIG. 13 shows a graph depicting flexural modulus (pounds per squareinch, PSI) per PPgMA loading levels (ppH) relative to weight of resinand filler combined of the example composite materials, according tosome implementations.

FIG. 14 shows a graph depicting viscosity (Pa·s) per PPgMA loadinglevels (parts per hundred, ppH) relative to weight of resin and fillercombined for example composite materials, according to someimplementations.

FIG. 15 shows a bar chart depicting flexural modulus (PSI) ofnon-oxidized carbon materials (DX C/F) and ozone (O₃)-treated carbonparticles for example composite materials, according to someimplementations.

FIG. 16 shows a bar chart depicting flexural modulus (PSI) of linearlow-density polyethylene (LLDPE) and polypropylene (PP) for examplecomposite materials, according to some implementations.

FIG. 17 shows a graph depicting flexural modulus (PSI) and elongation atbreak (%) per PPgMA loading levels (ppH) relative to weight of resin andfiller combined for example composite materials, according to someimplementations.

FIG. 18 shows a graph of measured percentage (%) increase of flexuralmodulus over neat resin per PPgMA loading levels (ppH) relative toweight of resin and filler combined for example composite materials,according to some implementations.

FIG. 19 shows a graph of oxygen content (atomic (at.) %) in ozone (O₃)treatment processes per time (minutes (min.)) of ozone-treating ofexample composite materials, according to some implementations.

FIG. 20 shows a graph of measured density (g/cm³) versus theoreticaldensity (g/cm³) of example composite materials, according to someimplementations.

FIG. 21 shows a graph of flexural modulus (PSI) and viscosity (Pa·s) perPPgMA loading levels (ppH) relative to weight of resin and fillercombined for example composite materials, according to someimplementations.

FIG. 22 shows a graph of flexural modulus (PSI) and viscosity (Pa·s)carbon loading (volume (vol.) %) of example composite materials,according to some implementations.

FIG. 23 shows a flowchart depicting an example operation for producingcomposite materials, according to some implementations.

FIG. 24 shows a flowchart depicting an example operation for formingcomposite materials, according to some implementations.

FIG. 25 shows a flowchart depicting an example operation for extrudingcomposite material, according to some implementations.

FIG. 26 shows a flowchart depicting an example operation for compactingcomposite material, according to some implementations.

FIG. 27 shows a flowchart depicting an example operation for pumping amixture of additional resin and a catalyst into a mold, according tosome implementations.

FIG. 28 shows a flowchart depicting an example operation for inserting astream of composite material into a mold, according to someimplementations.

FIG. 29 shows a flowchart depicting an example operation forpost-processing composite material, according to some implementations.

FIG. 30 shows a flowchart depicting an example operation for extrudingcomposite material through a cylindrical mold, according to someimplementations.

FIG. 31 shows a flowchart depicting an example operation for forming anitem with composite material, according to some implementations.

FIG. 32 shows a flowchart depicting an example operation for patterningcomposite material, according to some implementations.

FIG. 33 shows a flowchart depicting an example operation forpost-processing composite material, according to some implementations.

FIG. 34 shows a flowchart depicting an example operation for extractinga formed product from a mold containing composite material, according tosome implementations.

FIG. 35 shows a flowchart depicting an example operation for moldingcomposite material into one or more shapes, according to someimplementations.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

The following description is directed to some example implementationsfor the purposes of describing innovative aspects of this disclosure.However, a person having ordinary skill in the art will readilyrecognize that the teachings herein can be applied in a multitude ofdifferent ways. The described implementations can be implemented in anytype of material and can be used to provide a formative material used toprotect cases, coolers, phones, flashlights, travel gear, luggage,drinkware, backpacks, or the like. As such, the disclosedimplementations are not to be limited by the examples provided herein,but rather encompass all implementations contemplated by the attachedclaims. Additionally, well-known elements of the disclosure will not bedescribed in detail or will be omitted so as not to obscure the relevantdetails of the disclosure.

As described above, a composite material is produced from two or moreconstituent materials having dissimilar chemical and/or physicalproperties. Typical engineered composite materials include reinforcedconcrete and masonry composite wood, such as plywood, reinforcedplastics, such as fiber-reinforced polymer or fiberglass ceramic matrixcomposites (e.g., composite ceramic and metal matrices), metal matrixcomposites (MMCs), and/or other advanced composite materials. Compositematerials tend to be less expensive, lighter, stronger, and/or moredurable than common materials or their constituent (e.g., formative)materials.

Composite materials may be applied in a wide array of end-useapplication areas, such as sensing, actuation, computation, andcommunication into composites (“robotic materials”). Composite materialsmay also be used in constructing and/or forming buildings, bridges,structures (e.g., boat hulls and swimming pool panels), racing carbodies, shower stalls, bathtubs, storage tanks, imitation granite,cultured marble sinks and countertops, or the like. Composite materialsmay be used in general automotive applications, such as exposed panelingand impact absorption (e.g., for bumpers). Some composite materials maybe produced for spacecraft and/or aircraft, which may travel at morethan 1,000 miles per hour in demanding environments, such as outerspace.

Interleaving stiff and brittle epoxy based carbon fiber reinforcedpolymer laminates with flexible thermoplastic laminates can increasetoughness of composite materials, and thus increase impact resistance.Such interleaved composites demonstrate shape memory behavior withoutadditional shape memory polymers and/or shape memory alloys, such as PVCand carbon fiber reinforced polymer laminates interleaved withpolystyrene. Composite materials may include various types or classes,such as sandwich-structured composite materials, which may be formed byattaching two relatively thin and stiff skins to a lightweight and thickcore. Although a core material of a composite material may be relativelyweak, its higher thickness may provide a sandwich composite relativelyhigh bending stiffness while maintaining a relatively low density.

In addition, polyethylene (PE) and polypropylene (PP) blends appear toincrease efficiency for polymer waste recycling while maintainingoverall throughput sustainability. However, as the polyolefins arethermodynamically immiscible, they may form a binary system withdecreased performance (e.g., less toughness, etc.) as compared with thecharacteristics of various homopolymers. PE/PP blend compatibilizationcan be used to develop high-performance and cost-effective products,such as by using reactive and/or non-reactive compatibilizationtechniques to increase a brittle to ductile transition for the PE/PPblends. Nevertheless, products resulting from such techniques often failto meet the requirements for commercial applications with relativelyhigh demands. To address this, some PE/PP blend modifications mayinclude reinforcing synthetic or natural filler to have tailoredproperties.

Aspects of the present disclosure recognize that certain compositematerials may benefit from uniformly incorporating carbon particlesthroughout various blends. Unfortunately, relatively high carbon loadinglevels (e.g., >10 weight percent (wt. %)) may result in undesirableaggregation (e.g., clumping) of the carbon materials, which may resultin uncontrolled increases in viscosity and exceed rheologicalspecifications provided by customers. While the relatively unpredictableand uncontrollable aggregation of carbon particles may undesirablychange physical properties (e.g., toughness) of composite materials,composite materials with no carbon may not possess certain physicalproperties (such as controlled brittleness) that carbon can provide.

Various aspects of the subject matter disclosed herein relate to acomposite material, which may be formed from a combination ofthermoplastic resin mixed with polypropylene-graft-maleic anhydride(PPgMA). Carbon particles may be mixed in the combination. In this way,the composite material may include between 80 wt. % and 90 wt. % of thethermoplastic resin, between 0.5 wt. % and 15 wt. % of PPgMA, andbetween 0.1 wt. % to 7 wt. % of carbon particles. Each carbon particlemay be formed from interconnected three-dimensional (3D) graphenatedmaterials (e.g., referred to as “3D graphene”) self-nucleated without aseed particle. In addition, each carbon particle may have an exposedcarbon surface with carbon atoms bonded to molecular sites on adjacentPPgMA molecules. At least some carbon atoms may be oxidized with one ormore oxygen-containing groups. In some instances, oxidizing carbon atomsmay increase PPgMA molecules chemically bonding with adjacent carbonatoms per unit volume, and thus interaction between carbon atoms andPPgMA molecules may maintain a composite material density within ⁺/⁻3%of thermoplastic resin density and/or produce a predictable rheologicalprofile, such as with viscosity levels between 2,100 pascal-seconds(Pa·S) and approximately 700 Pa·S.

FIG. 1 shows micrographs 100 of example composite materials, accordingto some implementations. The micrographs 100 include a first micrograph110, which depicts a composite material withoutpolypropylene-graft-maleic anhydride (PPgMA), and a second micrograph120, which depicts a composite material including nitrogen-doped(n-doped) carbon particles and polypropylene-graft-maleic anhydride(PPgMA) at a loading level of 5.0 parts per hundred (ppH). The firstmicrograph 110 depicts carbon particles 115 which may cluster togetherto form one or more instances of a carbon agglomerated region 116.Carbon agglomeration in composite materials may result in uncontrolledincreases in viscosity, typically exceeding desired rheologicalspecifications and are therefore undesirable for many end-useapplication areas. Alternatively, the micrograph 120 depicts carbonparticles 115 throughout one or more instances of a uniformly dispersedregion 126. The relatively uniform distribution of the carbon particles115 throughout the uniformly dispersed region 126 may be attributed toan inclusion of PPgMA, which may infiltrate void regions (not shown forsimplicity) in the carbon particles 115. The carbon particles 115 maythus be at least partially separated by, for example, interconnectedPPgMA molecular units to form the uniformly dispersed region 126, whichmay cause the composite material to have a predictable rheologicalprofile, such as predictable density and/or viscosity values.

In some aspects, the composite material may be post-processed byinjection molding and used as a formative material for cases, coolers,phone cases, flashlights, travel gear, luggage, drinkware, backpacks, orthe like. In addition, the composite material depicted in the micrograph120 may be used as a formative material in a variety of end-useapplication areas in several industries, including (but not limited to)agriculture, construction, floor cleaning machinery, water treatment,outdoor (e.g., lawn and garden), environmental products, marine,aerospace, recreational equipment, sporting equipment, toys, furniture,medical, consumer articles, large containers, tanks, boxes, or the like.In some instances, fabrication methods used to produce the compositematerial include rotational molding, injection molding, blow molding,vacuum forming, thermoforming, extrusion, additive manufacturing (e.g.,3D printing), polymer casting, or another appropriate fabricationmethod.

In some instances, the composite material is formed by a combination ofa thermoplastic resin and maleated copolymers, maleic copolymers, and/ormaleated polymers. In some aspects, the thermoplastic resin may be orinclude a linear low-density polyethylene (LLDPE) resin including anethylene-butene copolymer and/or alpha-olefins. In some other aspects,the thermoplastic resin may be or include any type of polyethylenesystem, including LLDPE, linear polyethylene (LPE), metallocenepolyethylene (mPE), high-density polyethylene (HDPE), ultra-highmolecular weight (UHMW) polyethylene (PE) (UHMWPE), nylons,polypropylene, polyether ether ketone (PEEK), or the like. Thethermoplastic resin may also be or include any type of semi-crystallineand amorphous thermoplastic materials.

Example semi-crystalline thermoplastic materials may be opaque,flexible, and chemical-resistant and include standard thermoplastics(e.g., polypropylene (PP), high-density polyethylene (PE-HD or HDPE),low-density polyethylene (PE-LD or LDPE), and/or linear low densitypolyethylene (PE-LLD or LLDPE)), engineering thermoplastics (e.g., nylon46 or polyamide 46 (PA46), polyphthalamide (PPA), syndiotacticpolystyrene (SPS), thermoplastic elastomer (TPE), polybutyleneterephthalate (PBT), polyethylene terephthalate (PET), polyoxymethylene(POM), nylon 6,6 or polyamide 6,6 and nylon 6 or polyamide 6 (PA66 andPA6, respectively), and/or high-performance thermoplastics (e.g.,polyether ketone (PEK), PEEK, polyphenylene sulfide (PPS), and/orpolypropylene 11/12 (PP 11/12)).

Example amorphous thermoplastic materials may be transparent, brittle,and not chemical-resistant and include standard thermoplastics (e.g.,acrylonitrile butadiene styrene (ABS), polystyrene high-impact (PS-HI),polystyrene (PS), and/or polyvinylchloride (PVC)), engineeringthermoplastics (e.g., polycarbonate (PC), polycarbonate polyethyleneterephthalate (PC/PET), a thermoplastic alloy of (PC) polycarbonate and(ABS) acrylonitrile-butadiene-styrene (PC/ABS), modified polyphenyleneether (m-PPE), poly (methyl methacrylate) (PMMA), and/or styreneacrylonitrile (SAN)), and/or high-performance thermoplastics (e.g.,polyamide-imides (PAI), polyphenylsulfone (PPSU), polysulfone (PSU),and/or polyethersulfone (PES)).

In some implementations, the thermoplastic resin may be mixed withpolypropylene-graft-maleic anhydride (PPgMA) (or “maleatedpolypropylene”). In some instances, the PPgMA may have a PP contentbetween 80 weight percent (wt. %) and 99.9 wt. % with a correspondingbalance of maleic anhydride (MA) content between 20 wt. % and 0.01 wt.%. In some other implementations, the thermoplastic resin may be mixedwith polypropylene-co-acrylic acid (PP-co-AA), polyethylene-co-acrylicacid (PE-co-AA) or with a maleated copolymer including, for example,polyethylene-graft-maleic anhydride (PE-g-MA), polyethylene-alt-maleicanhydride (PE-alt-MA), polyisoprene-graft-maleic anhydride (PI-g-MA),polystyrene-graft-maleic anhydride (PS-g-MA), orpolystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleicanhydride. In such implementations, the maleated copolymer may have apolymer (e.g., PP, PE, polyisoprene (PI), or PS content between 80weight percent (wt. %) and 99.9 wt. % and a maleic anhydride (MA)content between 20 wt. % and 0.01 wt. %, and thus the composite materialmay include between 98.7 wt. %-100 wt. % polypropylene (PP) and between0.0 wt. %-1.3 wt. % maleic anhydride (MA).

In some implementations, the carbon particles 115 may be mixed such thatthe composite material includes between 80 wt. % and 90 wt. % ofthermoplastic resin, between 0.5 wt. % and 15 wt. % of PPgMA, andbetween 0.1 wt. % to 7 wt. % of carbon particles. Each of the carbonparticles may include carbon atoms chemically bonded to adjacent atomsof the thermoplastic resin and/or PPgMA, and the PPgMA may thus be acompatibilizer between the carbon particles and the thermoplastic resin.In some aspects, the carbon particles include a first region 117 havinga relatively low concentration of carbon particles per unit volume and asecond region 118 having a relatively high concentration of carbonparticles per unit volume. The first region 117 may be positionedadjacent to the second region 118. In some instances, the carbonparticles have one or more additional regions 119 that each have adifferent (e.g., higher or lower) concentration level than theimmediately preceding region. Any one or more of the first region 117,the second region 118, and the one or more additional regions 119 may besized identically or different to any other region. In this way, thecarbon particles 115 may be organized to attain predefined concentrationlevels per unit volume throughout the composite material.

In some implementations, the carbon particles 115 have exposed carbonsurfaces with carbon atoms (not shown for simplicity) bonded tomolecular sites on adjacent PPgMA molecules. The carbon atoms may beoxidized with one or more oxygen-containing groups. Interaction betweenthe carbon atoms and their adjacent PPgMA molecules may maintain adensity of the composite material within ⁺/⁻3% of a density of thethermoplastic resin. Pores may be formed within and/or between at leastsome of the carbon particles 115, the thermoplastic resin, and PPgMA,such that at least some of the pores may be infiltrated by PPgMA. Insome aspects, each pore may have a pore volume between 0.05 cubiccentimeters per gram (cm³/g) and 1.5 cm³/g. In addition, oxidation ofcarbon atoms may increase chemical bonding of PPgMA with adjacent carbonatoms per unit volume. In some instances, carbon particles may be formedfrom one or more interconnected crinkled 3D graphene sheets ornon-hollow carbon spherical particles (NHCS).

The composite material may be characterized by one or more physical,chemical, mechanical, and/or other properties. For example, a density ofthe composite material may be based at least in part on a collectivepore volume of the pores. In some instances, at least some carbon atomsmay chemically react with adjacent PPgMA molecules, changing rheologicalproperties of the composite material. In this way, the compositematerial may have a viscosity based on the thermoplastic resin, PPgMA,and the at least some carbon particles. In some aspects, the viscosityof the composite material may be based on loading levels of carbonparticles within the composite material. In some other aspects, theviscosity of the composite material may decrease proportionately toincreases in loading levels of PPgMA within the composite material.

In some aspects, the composite material may have a viscosity between2,100 pascal-seconds (Pa-s) and 500 Pa-s. In some instances, includingcarbon particles in the composite material may increase a flexuralmodulus and/or a tensile strength of the composite material. Forexample, the composite material may have a flexural modulus between107,500 pounds per square inch (PSI) and 117,500 PSI at a temperature of23° C. under ASTM D.790 at a 1% secant modulus value. In some instances,the composite material may have a maximum tensile elongation of 500%.The composite material may have a tunable melt flow rate between 4 gramsper min (g/min) to 8 g/min at a temperature of 190° C. In addition, thetensile strength of the composite material may be 30% to 100% higherthan composite materials not including carbon particles. At least somecarbon atoms may change chemical bonding behavior associated withsurrounding atoms of the thermoplastic resin and PPgMA molecules bychemically reacting with the PPgMA molecules. For example, interactionbetween at least some of the carbon particles and their respectiveadjacent PPgMA molecules may increase a mechanical reinforcement of thecomposite material by 1,000 PSI to 1,100 PSI per one part per hundred (1ppH) of PPgMA.

In at least one implementation, the carbon particles may be formed ofone or more non-tri-zone particles and/or tri-zone particles not shownfor simplicity. In some instances, each of the tri-zone particle may beformed of intertwined carbon fragments separated by mesopores not shownfor simplicity. A deformable perimeter may form upon coalescence withthe one or more non-tri-zone particles and/or tri-zone particles. Inaddition, the carbon particles may be formed of and/or includeaggregates and agglomerates. In some instances, each aggregate includesjoined tri-zone particles and a principal dimension between 10nanometers (nm) and 10 micrometers (μm). In some instances, mesoporesare interspersed throughout the aggregates, and each mesopore may have aprincipal dimension between 3.3 nanometers (nm) and 19.3 nm. Eachagglomerate may include joined aggregates that each have a principaldimension between approximately 0.1 μm and 1,000 μm. In some instances,macropores are interspersed throughout the aggregates, and eachmacropore may have a principal dimension between 0.1 μm and 1,000 μm. Insome aspects, at least some of the carbon particles function asnano-reinforcing members within the composite material. In this way, theMA may react with at least some of the nano-reinforcing members. Inaddition, PP may increase interfacial interaction between at least someof the nano-reinforcing members and the thermoplastic resin.

FIG. 2 shows a micrograph 200 of graphene materials 205 produced bysulfuric acid (H₂SO₄) exfoliation from graphite, according to someimplementations. In some aspects, at least some of the graphenematerials 205 coalesce with one or more additional instances of thegraphene materials 205 and produce at least some of the carbon particles115 depicted in FIG. 1 . In some other aspects, a shape and/or amorphology of at least some of the graphene materials 205 is and/orresembles a flat nanoplatelet. In addition, at least some of thegraphene materials 205 may have a “wavy” or “crinkled” morphology 210,which may indicate that at least some flat nanoplatelets are adjoined atone or more defined angles (rather than a straight, flat, or 180°angle), which may result in a surface area to volume ratio per unitvolume being relatively higher than for non-wavy or non-crinkledgraphene materials.

FIG. 3 shows micrographs 300 of microwave-energy based wavy and/orwrinkled graphene 305, according to some implementations. In someinstances, at least some of the microwave-energy based wavy and/orwrinkled graphene 305 may coalesce with one or more additional instancesof itself to produce at least some of the carbon particles 115 depictedin the micrograph 120 of FIG. 1 . In addition, at least some of themicrowave-energy based wavy and/or wrinkled graphene 305 may be oneexample of the graphene materials 205 of FIG. 2 . In some aspects, atleast some graphene nanoplatelets of the microwave-energy based wavyand/or wrinkled graphene 305 may adjoin together to define variousridges and valleys 315. In this way, at least some of the ridges andvalleys 315 may produce areas of increased flexibility within themicrowave-energy based wavy and/or wrinkled graphene 305, which may besuitable for infiltration by, for example, a polymeric substance (e.g.,PPgMA and/or the like). In some aspects, sp³-hybridized polymeric chains(e.g., polyethylene, PE), may demonstrate increased flexibility relativeto sp²-C chain conjugated polymers (e.g., poly(p-phenylene).

FIG. 4 shows a micrograph 400 of example carbon particles, according tosome implementations. In some aspects, at least some of the carbonparticles 405 may each be one example of one or more of the carbonparticles 115 depicted by the micrograph 120 of FIG. 1 . In addition, atleast some of the carbon particles 405 may be formed upon coalescence ofseveral instances of the graphene materials 205 and/or themicrowave-energy based wavy and/or wrinkled graphene 305. In someinstances, the carbon particles 405 may be separated from one another bya first multitude of pores 410 formed between adjacent instances of thecarbon particles 405. As shown in FIG. 4 , each of the carbon particles405 may be a porous structure containing additional multitudes of pores(e.g., including a second multitude of pores 420) produced byoverlapping secondary carbon particles 415. In various implementations,an average size of the first multitude of pores 410 may be larger thanan average size of the second multitude of pores 420. In variousimplementations, the second multitude of pores may be large enough toenable PPgMA molecules and/or other substances to infiltrate at leastsome of the carbon particles 405 to thereby produce, for example, thecomposite material depicted in the micrograph 120 of FIG. 1 .

FIG. 5A shows a diagram of an example of a carbon particle (e.g., atri-zone particle) shown in FIG. 4 , according to some implementations.In various implementations, the tri-zone particle 500A may be oneexample of any one or more of the carbon particles 115 depicted by themicrograph 120 of FIG. 1 . The tri-zone particle 500A may include threediscrete zones such as (but not limited to) a first zone 501, a secondzone 502, and a third zone 503. In some aspects, each of the zones501-503 surrounds and/or encapsulates a preceding zone. For example, thefirst zone 501 may be surrounded by or encapsulated by the second zone502, and the second zone 502 may be surrounded by or encapsulated by thethird zone 503. The first zone 501 may correspond to an inner region ofthe tri-zone particle 500A, the second zone 502 may correspond to anintermediate transition region of the tri-zone particle 500A, and thethird zone 503 may correspond to an outer region of the tri-zoneparticle 500A. In some aspects, the tri-zone particle 500A may include apermeable shell 505 that deforms in response to contact with one or moreadjacent non-tri-zone particles and/or tri-zone particles 500A.

In some implementations, the first zone 501 may have a relatively lowdensity, a relatively low electrical conductivity, and a relatively highporosity, the second zone 502 may have an intermediate density, anintermediate electrical conductivity, and an intermediate porosity, andthe third zone 503 may have a relatively high density, a relatively highelectrical conductivity, and a relatively low porosity. In some aspects,the first zone 501 may have a density of carbon material betweenapproximately 1.5 g/cc and 5.0 g/cc, the second zone 502 may have adensity of carbon material between approximately 0.5 g/cc and 3.0 g/cc,and the third zone 503 may have a density of carbon material betweenapproximately 0.0 and 1.5 g/cc. In other aspects, the first zone 501 mayinclude pores having a width between approximately 0 and 40 nm, thesecond zone 502 may include pores having a width between approximately 0and 35 nm, and the third zone 503 may include pores having a widthbetween approximately 0 and 30 nm. In some other implementations, thesecond zone 502 may not be defined for the tri-zone particle 500A. Inone implementation, the first zone 501 may have a principal dimension D₁between approximately 0 nm and 100 nm, the second zone 502 may have aprincipal dimension D₂ between approximately 20 nm and 150 nm, and thethird zone 503 may have a principal dimension D₃ of approximately 200nm.

Aspects of the present disclosure recognize that the unique layout ofthe tri-zone particle 500A and the relative dimensions, porosities, andelectrical conductivities of the first zone 501, the second zone 502,and the third zone 503 can be selected and/or modified achieve a desiredbalance between minimizing the polysulfide shuttle effect and maximizingthe specific capacity of a host battery. Specifically, in some aspects,the pores may decrease in size and volume from one zone to other. Insome implementations, the tri-zone particle may consist entirely of onezone with a range of pore sizes and pores distributions (e.g., poredensity). For the example of FIG. 5A, the pores 511 associated with thefirst zone 501 or the first porosity region have relatively large widthsand may be defined as macropores, the pores 512 associated with thesecond zone 502 or the second porosity region have intermediate-sizedwidths and may be defined as mesopores, and the pores 513 associatedwith the third zone 503 or the third porosity region have relativelysmall widths and may be defined as micropores.

A group of tri-zone particles 500A may be joined together to form anaggregate (not shown for simplicity), and a group of the aggregates maybe joined together to form an agglomerate (not shown for simplicity). Insome implementations, a plurality of mesopores may be interspersedthroughout the aggregates formed by respective groups of the carbonparticles 500A. In some aspects, a first porosity region may be at leastpartially encapsulated by the second porosity region such that arespective aggregate may include one or more mesopores and one or moremacropores. In one implementation, each mesopore may have a principaldimension between 3.3 nanometers (nm) and 19.3 nm, and each macroporemay have a principal dimension between 0.1 μm and 1,000 μm. In someinstances, the tri-zone particle 500A may include carbon fragmentsintertwined with each other and separated from one another by at leastsome of the mesopores.

In some implementations, the tri-zone particle 500A may include asurfactant or a polymer that includes one or more of styrene butadienerubber, polyvinylidene fluoride, poly acrylic acid, carboxyl methylcellulose, polyvinylpyrrolidone, and/or polyvinyl acetate that can actas a binder to join a group of the carbon materials together. In otherimplementations, the tri-zone particle 500A may include a gel-phaseelectrolyte or a solid-phase electrolyte disposed within at least someof the pores.

In some implementations, the tri-zone particle 500A may have a surfacearea of exposed carbon surfaces in an approximate range between 10 m²/gto 3,000 m²/g and/or a composite surface area (including othersubstances such as PPgMA micro-confined within pores) in an approximaterange between 10 m²/g to 3,000 m²/g. In one implementation, acomposition of matter including a multitude of tri-zone particles 500Amay have an electrical conductivity in an approximate range between 100S/m to 20,000 S/m at a pressure of 12,000 pounds per square in (psi) anda sulfur to carbon weight ratio between approximately 1:5 to 10:1.

FIG. 5B shows an example step function representative of the tri-zoneparticle of FIG. 5A, according to some implementations. As discussed,the pores distributed throughout the tri-zone particle 500A may havedifferent sizes, volumes, or distributions. In some implementations, theaverage pore volume may decrease based on a distance between a center ofthe tri-zone particle 500A and an adjacent zonae, for example, such thatpores associated with the first zone 501 or the first porosity regionhave a relatively large volume or pore size, pores associated with thesecond zone 502 or the second porosity region have an intermediatevolume, and pores associated with the third zone 503 or the thirdporosity region have a relatively small volume. The interior region hasa higher pore volume than the regions near the periphery. The regionwith higher pore volume provides for high sulfur loading whereas thelower pore volume outer regions mitigate the migration of polysulfidesduring cell cycling. In the example of FIG. 5B, the average pore volumein the inner region is approximately 3 ^(cc)/_(g), the average porevolume in the outermost region is approximately 0.5 ^(cc)/_(g) and theaverage pore volume in the intermediate region is between 0.5 ^(cc)/_(g)and 3 ^(cc)/_(g).

FIG. 6 shows a graph depicting an example distribution of pore volumeversus pore width of an example carbon particle, according to someimplementations. As depicted in the graph 600, pores associated with arelatively high pore volume may have a relatively low pore width, forexample, such that the pore width generally increases as the pore volumedecreases. In some aspects, pores having a pore width less thanapproximately 1.0 nm may be referred to as micropores, pores having apore width between approximately 3 and 11 nm may be referred to asmesopores, and pores having a pore width greater than approximately 24nm may be referred to as macropores.

FIG. 7A shows a micrograph 700 of example carbon particles, aggregates,and/or agglomerates depicted in FIG. 4 and/or FIG. 5A, according to someimplementations. In some aspects, the carbon particles depicted in FIG.7A may be one example of the carbon particles 115 depicted in themicrograph 120 of FIG. 1 and/or other carbon particles described in thepresent disclosure. In some implementations, each of the carbonstructures 702 may have a substantially hollow a core region surroundedby various monolithic carbon growths and/or layering. In some aspects,the monolithic carbon growths and/or layering may be examples of thevarious carbon structures, growths and/or layering described withreference to FIGS. 2 through 4 . In some instances, the carbonstructures 702 may include several concentric multi-layered fullerenesand/or similarly shaped carbon structures organized at varying levels ofdensity and/or concentration. For example, the actual final shape, size,and graphene configuration of each of the carbon structures 702 maydepend on various manufacturing processes. The carbon structures 702may, in some aspects, demonstrate poor water solubility. As such, insome implementations, non-covalent functionalization may be utilized toalter one or more dispersibility properties of the carbon structures 702without affecting the intrinsic properties of the underlying carbonnanomaterial. In some aspects, the underlying carbon nanomaterial may beformative a sp² carbon nanomaterial. In some implementations, each ofthe carbon structures 702 may have a diameter between approximately 20and 500 nm. In various implementations, groups of the carbon structures702 may coalesce and/or join together to form the aggregates 704. Inaddition, groups of the aggregates 704 may coalesce and/or join togetherto form the agglomerates 706. In some aspects, one or more of the carbonstructures 702, the aggregates 704, and/or the agglomerates 706 may beused to form one or more of the carbon particles 115 depicted in themicrograph 120 of FIG. 1 .

FIG. 7B shows a micrograph 750 of an aggregate formed of carbonmaterial, according to some implementations. In some implementations,the aggregate 760 may be an example of one of the aggregates 704 of FIG.7A. In one implementation, exterior carbon shell-type structures 752 mayfuse together with carbons provided by other carbon shell-typestructures 754 to form a carbon structure 756. A group of the carbonstructures 756 may coalesce and/or join with one another to form theaggregate 760. In some aspects, a core region 758 of each of the carbonstructures 756 may be tunable, for example, in that the core region 758may include various defined concentration levels of interconnectedgraphene structures and/or carbon particles, as described with referenceto FIG. 5A and/or FIG. 5B. In some implementations, some of the carbonstructures 756 may have a first concentration of interconnected carbonsapproximately between 0.1 g/cc and 2.3 g/cc at or near the exteriorcarbon shell-type structure 752. Each of the carbon structures 756 mayhave pores to transport lithium cations (Li⁺) extending inwardly fromtoward the core region 758.

In some implementations, the pores in each of the carbon structures 756may have a width or dimension between approximately 0.0 nm and 0.5 nm,between approximately 0.0 and 0.1 nm, between approximately 0.0 and 6.0nm, or between approximately 0.0 and 35 nm. Each carbon structures 756may also have a second concentration at or near the core region 758 thatis different than the first concentration. For example, the secondconcentration may include several relatively lower-density carbonregions arranged concentrically. In one implementation, the secondconcentration may be lower than the first concentration at betweenapproximately 0.0 g/cc and 1.0 g/cc or between approximately 1.0 g/ccand 1.5 g/cc. In some aspects, the relationship between the firstconcentration and the second concentration may be used to achieve abalance between confining sulfur or polysulfides within a respectiveelectrode and maximizing the transport of lithium cations (Li⁺). Forexample, sulfur and/or polysulfides may travel through the firstconcentration and be at least temporarily confined within and/orinterspersed throughout the second concentration during operationalcycling of a lithium-sulfur battery.

In some implementations, at least some of the carbon structures 756 mayinclude CNO oxides organized as a monolithic and/or interconnectedgrowths and be produced in a thermal reactor. For example, the carbonstructures 756 may be decorated with cobalt nanoparticles according tothe following example recipe: cobalt(II) acetate (C₄H₆CoO₄), the cobaltsalt of acetic acid (often found as tetrahydrate Co(CH₃CO₂)₂·4H₂O, whichmay be abbreviated as Co(Oac)₂·4 H₂O, may be flowed into the thermalreactor at a ratio of approximately 59.60 wt % corresponding to 40.40 wt% carbon (referring to carbon in CNO form), resulting in thefunctionalization of active sites on the CNO oxides with cobalt, showingcobalt-decorated CNOs at a 15,000× level, respectively. In someimplementations, suitable gas mixtures used to produce Carbon #29 and/orthe cobalt-decorated CNOs may include the following steps:

-   -   Ar purge 0.75 standard cubic feet per minute (scfm) for 30 min;    -   Ar purge changed to 0.25 scfm for run;    -   temperature increase: 25° C. to 300° C. 20 mins; and    -   temperature increase: 300° C.-500° C. 15 mins.

Carbon materials described with reference to FIGS. 7A and 7B may includeor otherwise be formed from one or more instances of graphene, which mayinclude a single layer of carbon atoms with each atom bound to threeneighbors in a honeycomb structure. The single layer may be a discretematerial restricted in one dimension, such as within or at a surface ofa condensed phase. For example, graphene may grow outwardly only in thex and y planes (and not in the z plane). In this way, graphene may be atwo-dimensional (2D) material, including one or several layers with theatoms in each layer strongly bonded (such as by a plurality ofcarbon-carbon bonds) to neighboring atoms in the same layer.

In some implementations, graphene nanoplatelets (e.g., formativestructures included in each of the carbon structures 756) may includemultiple instances of graphene, such as a first graphene layer, a secondgraphene layer, and a third graphene layer, all stacked on top of eachother in a vertical direction. Each of the graphene nanoplatelets, whichmay be referred to as a GNP, may have a thickness between 1 nm and 3 nm,and may have lateral dimensions ranging from approximately 100 nm to 100μm. In some implementations, graphene nanoplatelets may be produced bymultiple plasma spray torches arranged sequentially by roll-to-roll(“R2R”) production. In some aspects, R2R production may includedeposition upon a continuous substrate that is processed as a rolledsheet, including transfer of 2D material(s) to a separate substrate. Insome instances, the plasma spray torches used in the described R2Rprocesses may spray carbon materials at different concentration levelsto produce specific concentration levels of graphene nanoplatelets.Therefore, R2R processes may provide a fine level of tunability forproducing the carbon particles 115 depicted in the micrograph 120 ofFIG. 1 , the carbon particles 405 depicted in the micrograph 400 of FIG.4 , and/or other carbon particles as described elsewhere in the presentdisclosure.

FIG. 8 shows a graph 800 depicting cumulative pore volume versus porewidth for micropores and mesopores dispersed throughout the carbonparticles 405 depicted in the micrograph 400 of FIG. 4 , according tosome implementations. As used herein, “Carbon 1” refers to structuredcarbon materials including mostly micropores (such as less than 5 nm inprincipal dimension), and “Carbon 2” refers to structured carbonmaterials including mostly mesopores (such as between approximately 20nm to 50 nm in principal dimension). In some implementations, anelectrode suitable for use in one of the batteries disclosed herein maybe prepared to have the pore size versus pore distribution depicted inthe graph 800.

FIG. 9 shows an example configuration 900 of the example carbonparticles depicted in FIG. 4 , according to some implementations. Insome implementations, the configuration 900 may be one example of one ormore agglomerates of the carbon particles 115 depicted in the micrograph120, the first region 117, the second region 118, one or more additionalregions 119 of FIG. 1 , or other carbon particles described elsewhere inthe present disclosure. In one implementation, the configuration 900includes a first porous carbon region 910 and a second porous carbonregion 920 positioned adjacent to the first porous carbon region 910.The first porous carbon region 910 may be formed of a firstconcentration level of carbon materials, and the second porous carbonregion 920 formed of a second concentration level of carbon materialsdissimilar to the first concentration level of carbon materials. Forexample, the second porous carbon region 920 may have a lowerconcentration level of carbon materials than the first porous carbonregion 910 as shown in FIG. 9 . In some aspects, additional porouscarbon regions (not shown in FIG. 9 for simplicity) maybe coupled withat least the second porous carbon region 920.

Specifically, these additional porous carbon regions may be arranged inorder of incrementally decreasing concentration levels of carbonmaterials in a direction away from the first porous carbon region 910 toprovide for complete tunability. That is, in one implementation, thesecond porous carbon region 920 may face a desired region (e.g., thefirst region 117 depicted in the micrograph 120 of FIG. 1 ) and thefirst porous carbon region 910 of the configuration 900 may bepositioned pursuant to customer specifications. In this way, densercarbon regions, such as the first porous carbon region 910, mayfacilitate relatively low levels of substance (e.g., PPgMA and/or thelike) between adjacent contact points of carbon materials, while sparsercarbon regions, such as the second porous carbon region 920, mayfacilitate relatively high levels of substance infiltration. In someimplementations, additional carbon regions coupled with and positionedadjacent to the second porous carbon region 920 may have a lower densityof carbon materials than the second porous carbon region 920. In thisway, the additional carbon regions of lower density may accommodatehigher levels of lithium ion transport to, for example, permit fortuning of various performance characteristics of composite materialsincluding the configuration 900.

In one implementation, the first porous carbon region 910 may includefirst non-tri-zone particles 911. The configuration of the firstnon-tri-zone particles 911 within the first porous carbon region is oneexample configuration. Other placements, orientations, alignments and/orthe like are possible for the non-tri-zone particles. In some aspects,each non-tri-zone particle may be an example of one or more carbonmaterials disclosed elsewhere in the present disclosure. The firstporous carbon region 910 may also include first tri-zone particles 912interspersed throughout the first non-tri-zone particles 911 as shown inFIG. 9 , or positioned in any other placement, orientation, orconfiguration. Each first tri-zone particle 912 may be one example ofthe tri-zone particle 500A of FIG. 5A. In addition, or the alternative,each first tri-zone-particle 912 may include first carbon fragments 913intertwined with each other and separated from one another by mesopores914. Each tri-zone-particle may have a first deformable perimeter 915configured to coalesce with adjacent first non-tri-zone particles 911and/or first tri-zone particles 912.

The first porous carbon region 910 may also include first aggregates916, where each aggregate includes a multitude of the first tri-zoneparticles 912 joined together. In one or more particular examples, eachfirst aggregate may have a principal dimension in a range between 10nanometers (nm) and 10 micrometers (μm). The mesopores 914 may beinterspersed throughout the first plurality of aggregates, where eachmesopore has a principal dimension between 3.3 nanometers (nm) and 19.3nm. In addition, the first porous carbon region 910 may include firstagglomerates 917, where each agglomerate includes a multitude of thefirst aggregates 916 joined to each other. In some aspects, each firstagglomerate 917 may have a principal dimension in an approximate rangebetween 0.1 μm and 1,000 μm. Macropores 918 may be interspersedthroughout the first aggregates 916, where each macropore may have aprincipal dimension between 0.1 μm and 1,000 μm. In someimplementations, one or more of the above-discussed carbon materials,allotropes and/or structures may be one or more examples of that shownin FIGS. 7A and 7B.

The second porous carbon may include second non-tri-zone particles 921,which may be one example of the first non-tri-zone particles 911. Thesecond porous carbon region 920 may include second tri-zone particles99, which may each be one example of each of the first tri-zoneparticles 912 and/or may be one example of the tri-zone particle 500A ofFIG. 5A. In addition, or the alternative, each second tri-zone particle922 may include second carbon fragments 923 intertwined with each otherand separated from one another by the mesopores 914. Each secondtri-zone particle 922 may have a second deformable perimeter 925configured to coalesce with one or more adjacent second non-tri-zoneparticles 921 or second tri-zone particles 99.

The second porous carbon may include second non-tri-zone particles 921,which may be one example of the first non-tri-zone particles 911. Thesecond porous carbon region 920 may include second tri-zone particles922, which may each be one example of each of the first tri-zoneparticles 912 and/or may be one example of the tri-zone particle 500A ofFIG. 5A. In addition, or the alternative, each second tri-zone particle922 may include second carbon fragments 923 intertwined with each otherand separated from one another by the mesopores 914. Each secondtri-zone particle 922 may have a second deformable perimeter 925configured to coalesce with one or more adjacent second non-tri-zoneparticles 921 or second tri-zone particles 922.

In addition, the second porous carbon region 920 may include secondaggregates 926, where each second aggregate 926 may include a multitudeof the second tri-zone particles 922 joined together. In one or moreparticular examples, each second aggregate 926 may have a principaldimension in a range between 10 nanometers (nm) and 10 micrometers (μm).The mesopores 914 may be interspersed throughout the second aggregates926, each mesopore may have a principal dimension between 3.3 nanometers(nm) and 19.3 nm. Further, the second porous carbon region 920 mayinclude second agglomerates 927, each second agglomerate 927 may includea multitude of the second aggregates 926 joined to each other, whereeach agglomerate may have a principal dimension in an approximate rangebetween 0.1 μm and 1,000 μm. The macropores 918 may be interspersedthroughout the second plurality of aggregates, where each macroporehaving a principal dimension between 0.1 μm and 1,000 μm. In someimplementations, one or more of the above-discussed carbon materials,allotropes and/or structures may be one or more examples of that shownin FIGS. 9A and 9B.

In one implementation, the first porous carbon region 910 and/or thesecond porous carbon region 920 may include a selectively permeableshell (not shown in FIG. 9 for simplicity), which may form a separatedliquid phase on the first porous carbon region 910 or the second porouscarbon region 920, respectively. An electrolyte, such as any of theelectrolytes disclosed in the present disclosure, may be dispersedwithin the first porous carbon region and/or the second porous carbonregion for lithium ion transport associated with lithium-sulfur batterydischarge-charge operational cycling.

In one or more particular examples, the first porous carbon region 910may have an electrical conductivity in an approximate range between 500S/m to 20,000 S/m at a pressure of 12,000 pounds per square in (psi).The second porous carbon region 920 may have an electrical conductivityin an approximate range between 0 S/m to 500 S/m at a pressure of 12,000pounds per square in (psi). The first agglomerates 917 and/or secondagglomerates 927 may include aggregates connected to each other with oneor more polymer-based binders.

In some aspects, each first tri-zone particle 912 may have a firstporosity region (not shown in FIG. 9 for simplicity) located around acenter of the first tri-zone particle 912. Similarly, each secondtri-zone particle 922 may have a first porosity region (not shown inFIG. 9 for simplicity) located around a center of the second tri-zoneparticle 922. The first porosity region may include first pores. Asecond porosity region (not shown in FIG. 9 for simplicity) may surroundthe first porosity region. The second porosity region may include secondpores. In one implementation, the first pores may define a first poredensity, and the second pores may define a second pore density that isdifferent the first pore density.

In some aspects, the mesopores 914 may be grouped into first mesoporesand second mesopores (both not shown in FIG. 9 for simplicity). In oneor more particular examples, the first mesopores may have a firstmesopore density, and the second mesopores may have a second mesoporedensity that is different than the first mesopore density. In addition,the macropores 918 may be grouped into first macropores that may have afirst pore density, and second macropores (both not shown in FIG. 9 forsimplicity) that may have a second pore density different than the firstpore density.

FIG. 10 shows a diagram 1000 of chemical structure components 1005 ofpolypropylene-graft-maleic anhydride (PPgMA), according to someimplementations. PPgMA is a 2-component molecule, includingpolypropylene (PP) and maleic anhydride (MA). In some aspects, PPgMA maybe provided in the form of beads and have a number-averaged molecularweight (M_(n)) of approximately 3,900 and a weight-averaged molecularweight (M_(w)) of approximately 9,100 as determined by gel permeationchromatography (GPC). Typical composite material compositions mayinclude loading levels of approximately 8 wt. %-10 wt. % of MW with thebalance of PP. In some instances, the measured viscosity of PPgMA may beapproximately 4.0 poise at a temperature of approximately 190° C. PPgMAmay have a melting point (mp) of approximately 156° C. and anapproximate density of 0.934 ^(g)/_(mL) at 25° C.

FIG. 11 shows example chemical structures 1100 including a chemicalreaction mechanism 1105 for producing the PPgMA depicted in FIG. 10 andfor ozone-treating graphene surfaces, according to some implementations.For example, as shown by the chemical reaction mechanism 1105, MA maybehave as a reactive group and react with one or more other chemicalsubstances (e.g., hexan-1-ol) via an open ring reaction, which mayproduce one or more intermediary products that undergo one or moreadditional chemical reactions to produce a completed molecule 1110. Insome aspects, the completed molecule 1110 may chemically react withother instances of the completed molecule 1110 to produce PPgMA forincorporation in the composite material of FIG. 1 .

In some implementations, the composite material of FIG. 1 mayincorporate at least some of the carbon particles 115. In some aspects,the carbon particles 115 have exposed carbon surfaces (e.g.,ozone-treaded (oxidized) graphene surfaces 1115) and carbon atoms bondedto molecular sites on adjacent PPgMA molecules. At least some of thecarbon atoms may be oxidized with one or more oxygen-containing groups.By oxidating the carbon atoms, more PPgMA molecules may chemically bondwith adjacent carbon atoms per unit volume. In this way, interactionbetween carbon atoms and PPgMA molecules may maintain composite materialdensity within ⁺/⁻3% of thermoplastic resin density and have apredictable rheological profile (such as with viscosity levels between2,100 pascal-seconds (Pa·S) and approximately 700 Pa·S).

FIG. 12 shows a graph 1200 depicting intensity (relative absorbance) perwavenumber (cm⁻¹), according to some implementations. The graph 1200indicates example observed properties of the composite material of FIG.1 . As depicted in the graph 1200, each of oxidized graphene, PPgMAgrafted graphene, and neat PPgMA have a different intensity.

FIG. 13 shows a graph 1300 depicting flexural modulus (PSI) per PPgMAloading levels (ppH) relative to weight of resin and filler combined ofthe example composite materials of FIG. 1 , according to someimplementations. The graph 1300 indicates example observed properties ofthe composite material of FIG. 1 . As depicted in the graph 1300, eachof neat resin (e.g., thermoplastic resin without any carbon loadinglevels), 1 volume (vol.) % carbon particle loading, and 3 vol. % carbonparticle loading has a distinct flexural modulus (PSI) profile per PPgMAloading levels (ppH) relative to weight of resin and filler combined.

FIG. 14 shows a graph 1400 depicting viscosity (Pa·s) per PPgMA loadinglevels (parts per hundred, ppH) relative to weight of resin and fillercombined of the example composite materials of FIG. 1 , according tosome implementations. The graph 1400 indicates example observedproperties of the composite material of FIG. 1 . As depicted in thegraph 1400, each of 1 volume (vol.) % carbon particle loading and 3 vol.% carbon particle loading has a distinct viscosity (Pa·s) per PPgMAloading level (ppH) relative to weight of resin and filler combined.

FIG. 15 shows a bar chart 1500 depicting flexural modulus (PSI) ofnon-oxidized carbon materials (DX C/F) and ozone (O₃)-treated carbonparticles for the example composite materials of FIG. 1 , according tosome implementations. The bar chart 1500 indicates example observedproperties of the composite material of FIG. 1 .

FIG. 16 shows a bar chart 1600 depicting flexural modulus (PSI) oflinear low-density polyethylene (LLDPE) and polypropylene (PP) for theexample composite materials of FIG. 1 , according to someimplementations. The bar chart 1600 indicates example observedproperties of the composite material of FIG. 1 . As depicted in the barchart 1600, PP has a higher PSI than LLDPE. Blending of the LLDPE and PPmay increase their reinforcement of, for example, the carbon particles115 of FIG. 1 . In some instances, a combination of the LLDPE and PP maybe infiltrated into open porous regions of the carbon particles 115(and/or as described with respect to the configuration 900 of FIG. 9 )to enhance the physical properties of the composite material.

FIG. 17 shows a graph 1700 depicting flexural modulus (PSI) andelongation at break (%) per PPgMA loading levels (ppH) relative toweight of resin and filler combined of the example composite materialsof FIG. 1 , according to some implementations. The graph 1700 indicatesexample observed properties of the composite material of FIG. 1 .

FIG. 18 shows a graph 1800 of measured percentage (%) increase offlexural modulus over neat resin per PPgMA loading levels (ppH) relativeto weight of resin and filler combined of the example compositematerials of FIG. 1 , according to some implementations. The graph 1800indicates example observed properties of the composite material of FIG.1 .

FIG. 19 shows a graph 1900 of oxygen content (atomic (at.) %) in ozone(O₃) treatment processes per time (minutes (min.)) of ozone-treating ofthe example composite materials of FIG. 1 , according to someimplementations. The graph 1900 indicates example properties of thecomposite material of FIG. 1 observed during ozone-treatment (e.g.,oxidation of carbon atoms provided by exposed carbon surfaces).

FIG. 20 shows a graph 2000 of measured density (g/cm³) versustheoretical density (g/cm³) of the example composite materials of FIG. 1, according to some implementations. The graph 2000 indicates exampleobserved properties of the composite material of FIG. 1 .

FIG. 21 shows a graph 2100 of flexural modulus (PSI) and viscosity(Pa·s) per PPgMA loading levels (ppH) relative to weight of resin andfiller combined of the example composite materials of FIG. 1 , accordingto some implementations. The graph 2100 indicates example observedproperties of the composite material of FIG. 1 .

FIG. 22 shows a graph 2200 of flexural modulus (PSI) and viscosity(Pa·s) carbon loading (volume (vol.) %) of the example compositematerials of FIG. 1 , according to some implementations. The graph 2200indicates example observed properties of the composite material of FIG.1 .

FIG. 23 shows a flowchart depicting an example operation 2300 forproducing composite materials depicted in the micrographs 120 of FIG. 1, according to some implementations. In various implementations, theoperation 2300 may be performed in one or more reactors, and the one ormore reactors may include a thermal reactor chamber, a plasma reactor, aspray dryer, an atomizer, or any other suitable chemical processingapparatus. In some aspects, the operation 2300 begins at block 2302 withsupplying a thermoplastic resin having an initial density. The operationcontinues at block 2304 with mixing a dispersion of apolypropylene-graft-maleic anhydride (PPgMA) throughout thethermoplastic resin, the PPgMA formed of a plurality of interconnectedPPgMA molecules. The operation continues at block 2306 with distributinga plurality of carbon particles throughout the thermoplastic resin andthe plurality of interconnected PPgMA molecules, the plurality of carbonparticles having a pore volume between 0.05 cubic centimeters per gram(cm³/g) and 1.5 cm³/g uniformly dispersed within a combination of thethermoplastic resin and the PPgMA. The operation continues at block 2308with forming, by rotational molding, the composite material based on acombination of the thermoplastic resin, the PPgMA, and at least some ofthe plurality of carbon particles, where chemical bonding between carbonatoms provided by at least some of the plurality of carbon particles andtheir respective adjacent interconnected PPgMA molecules is configuredto increase flexural modulus of the composite material while maintainingthe final density of the composite material within a tolerance limit of+/−3% deviation from the initial density of the thermoplastic resin,where the tolerance limit is based on the pore volume.

FIG. 24 shows a flowchart depicting an example operation 2400 forforming the composite materials produced in FIG. 23 , according to someimplementations. In various implementations, the operation 2400 may beperformed in a mold and/or molding apparatus. In some aspects, theoperation 2400 begins at block 2402 with compressing the compositematerial in one or more directions. The operation continues at block2404 with forming one or more of a sheet or a plate based on thecompression of the composite material.

FIG. 25 shows a flowchart depicting an example operation 2500 forextruding the composite material produced in FIG. 23 , according to someimplementations. In various implementations, the operation 2500 may beperformed in a material extruder. In some aspects, the operation 2500begins at block 2502 with extruding the composite material through adie. The operation continues at block 2504 with forming an item based onextrusion of the composite material.

FIG. 26 shows a flowchart depicting an example operation 2600 forcompacting the composite material produced in FIG. 23 , according tosome implementations. In various implementations, the operation 2600 maybe performed in a mold. In some aspects, the operation 2600 begins atblock 2602 with preparing a mold using one or more of a hand lay-upprocess or a spray process. The operation continues at block 2604 withcompacting the composite material using hand-rollers.

FIG. 27 shows a flowchart depicting an example operation 2700 forpumping a mixture of additional resin and a catalyst into a mold usedfor forming the composite material produced in FIG. 23 , according tosome implementations. In various implementations, the operation 2700 maybe performed in a mold. In some aspects, the operation 2700 begins atblock 2702 with drying the composite material to produce a driedcomposite material. The operation continues at block 2704 with insertingthe dried composite material into a mold. The operation continues atblock 2706 with pumping a mixture of additional resin and a catalystinto the mold.

FIG. 28 shows a flowchart depicting an example operation 2800 forinserting a stream of the composite material produced in FIG. 23 into amold, according to some implementations. In various implementations, theoperation 2800 may be performed in a mold. In some aspects, theoperation 2800 begins at block 2802 with inserting a stream of thecomposite material into a mold. The operation continues at block 2804with inserting a stream of linear low-density polyethylene (LLDPE) intothe mold. The operation continues at block 2806 with inserting acatalyst into the mold. The operation continues at block 2808 withmixing the composite material, the thermoplastic resin, and the catalystwithin the mold.

FIG. 29 shows a flowchart depicting an example operation 2900 forpost-processing the composite material produced in FIG. 23 , accordingto some implementations. In various implementations, the operation 2800may be performed in a vacuum-assisted resin transfer molding (VARTM)apparatus. In some aspects, the operation 2900 begins at block 2902 withpost-processing the composite material using a vacuum-assisted resintransfer molding (VARTM) technique including drawing the compositematerial into a mold using a vacuum.

FIG. 30 shows a flowchart depicting an example operation 3000 forextruding the composite material through a cylindrical mold, accordingto some implementations. In various implementations, the operation 3000may be performed in a mold. In some aspects, the operation 3000 beginsat block 3002 with extruding the composite material through acylindrical mold to produce a composite wire. The operation continues atblock 3004 with winding the composite wire along an axis to produce afilament-wound composite.

FIG. 31 shows a flowchart depicting an example operation 3100 forforming an item with the composite material produced in FIG. 23 ,according to some implementations. In various implementations, theoperation 3100 may be performed in a heated bath. In some aspects, theoperation 3100 begins at block 3102 with generating a semi-moltencomposite wire by passing a wire of the composite material through abath maintained at above 22° C. The operation continues at block 3104with forming an item by passing the semi-molten composite wire throughone or more guides.

FIG. 32 shows a flowchart depicting an example operation 3200 forpatterning the composite material produced in FIG. 23 , according tosome implementations. In various implementations, the operation 3200 maybe performed in or on a patterning tool. In some aspects, the operation3200 begins at block 3202 with cutting the composite material into oneor more predefined patterns. The operation continues at block 3204 withlaying the one or more predefined patterns on a surface. The operationcontinues at block 3206 with rolling over the one or more predefinedpatterns on the surface with a mandrel.

FIG. 33 shows a flowchart depicting an example operation 3300 forpost-processing the composite material produced in FIG. 23 , accordingto some implementations. In various implementations, the operation 3300may be performed in or on a patterning tool. In some aspects, theoperation 3300 begins at block 3302 with forming a sheet of thecomposite material. The operation continues at block 3304 with pouringsliced fiberglass on top of the sheet of the composite material. Theoperation continues at block 3306 with covering the sheet of thecomposite material and the sliced fiberglass with an additional layer ofthe composite material.

FIG. 34 shows a flowchart depicting an example operation 3400 forextracting a formed product from a mold containing the compositematerial produced in FIG. 23 , according to some implementations. Invarious implementations, the operation 3400 may be performed in amaterial extruder. In some aspects, the operation 3400 begins at block3402 with injecting the composite material in a molten state into amold. The operation continues at block 3404 with extracting a formedproduct from the mold by cooling the composite material within the mold.

FIG. 35 shows a flowchart depicting an example operation 3500 formolding the composite material produced in FIG. 23 into one or moreshapes, according to some implementations. In various implementations,the operation 3500 may be performed in a mold. In some aspects, theoperation 3500 begins at block 3502 with molding the composite materialinto one or more shapes using one of vacuum compression molding,rotational molding, blow molding, or injection over-molding.

As used herein, a phrase referring to “at least one of” or “one or moreof” a list of items refers to any combination of those items, includingsingle members. For example, “at least one of: a, b, or c” is intendedto cover the possibilities of: a only, b only, c only, a combination ofa and b, a combination of a and c, a combination of b and c, and acombination of a and b and c.

The various illustrative components, logic, logical blocks, modules,circuits, operations, and algorithm processes described in connectionwith the implementations disclosed herein may be implemented aselectronic hardware, firmware, software, or combinations of hardware,firmware, or software, including the structures disclosed in thisspecification and the structural equivalents thereof. Theinterchangeability of hardware, firmware and software has been describedgenerally, in terms of functionality, and illustrated in the variousillustrative components, blocks, modules, circuits and processesdescribed above. Whether such functionality is implemented in hardware,firmware or software depends upon the application and design constraintsimposed on the overall system.

Various modifications to the implementations described in thisdisclosure may be readily apparent to persons having ordinary skill inthe art, and the generic principles defined herein may be applied toother implementations without departing from the spirit or scope of thisdisclosure. Thus, the claims are not intended to be limited to theimplementations shown herein but are to be accorded the widest scopeconsistent with this disclosure, the principles and the novel featuresdisclosed herein.

Additionally, various features that are described in this specificationin the context of separate implementations also can be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation also can beimplemented in multiple implementations separately or in any suitablesubcombination. As such, although features may be described above incombination with one another, and even initially claimed as such, one ormore features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one more exampleprocesses in the form of a flowchart or flow diagram. However, otheroperations that are not depicted can be incorporated in the exampleprocesses that are schematically illustrated. For example, one or moreadditional operations can be performed before, after, simultaneously, orbetween any of the illustrated operations. In some circumstances,multitasking and parallel processing may be advantageous. Moreover, theseparation of various system components in the implementations describedabove should not be understood as requiring such separation in allimplementations, and it should be understood that the described programcomponents and systems can generally be integrated together in a singleproduct or packaged into multiple products.

What is claimed is:
 1. A method for continuously producing a compositematerial having a final density, the method comprising: supplying athermoplastic resin having an initial density; mixing a dispersion of apolypropylene-graft-maleic anhydride (PPgMA) throughout thethermoplastic resin; distributing a plurality of carbon particlesthroughout the thermoplastic resin including PPgMA, wherein at leastsome of the plurality of carbon particles are formed from one or more ofa plurality of interconnected crinkled 3D graphene sheets or a pluralityof non-hollow carbonaceous spherical particles (NHCS); and forming thecomposite material including the thermoplastic resin, PPgMA, and theplurality of carbon particles, wherein the final density of thecomposite material is within +/−3% of the initial density of thethermoplastic resin.
 2. The method of claim 1, wherein the method isperformed on one or more of a dual-screw mixer or compounder, aninjection molder, or a pelletizing machine.
 3. The method of claim 1,further comprising: compressing the composite material in one or moredirections; and forming one or more of a sheet or a plate based on thecompression of the composite material.
 4. The method of claim 1, furthercomprising: extruding the composite material through a die; and formingan item based on extrusion of the composite material.
 5. The method ofclaim 1, further comprising: molding the composite material as aformative material; and forming an item based on molding the compositematerial.
 6. The method of claim 1, further comprising post-processingthe composite material using a resin-transfer molding techniquecomprising: drying the composite material to produce a dried compositematerial; inserting the dried composite material into a mold; andpumping a mixture of additional resin and a catalyst into the mold. 7.The method of claim 1, further comprising post-processing the compositematerial using a reaction injection molding technique comprising:inserting a stream of the composite material into a mold; inserting astream of linear low-density polyethylene (LLDPE) into the mold; andinserting a catalyst into the mold; mixing the composite material, thethermoplastic resin, and the catalyst within the mold.
 8. The method ofclaim 1, further comprising: post-processing the composite materialusing a vacuum-assisted resin transfer molding (VARTM) techniqueincluding drawing the composite material into a mold using a vacuum. 9.The method of claim 1, further comprising post-processing the compositematerial using a filament winding fabrication technique comprising:extruding the composite material through a cylindrical mold to produce acomposite wire; and winding the composite wire along an axis to producea filament-wound composite.
 10. The method of claim 1, furthercomprising post-processing the composite material using a pultrusiontechnique comprising: generating a semi-molten composite wire by passinga wire of the composite material through a bath maintained at above 22°C.; and forming an item by passing the semi-molten composite wirethrough one or more guides.
 11. The method of claim 1, furthercomprising post-processing the composite material using tube rollingcomprising: cutting the composite material into one or more predefinedpatterns; laying the one or more predefined patterns on a surface; androlling over the one or more predefined patterns on the surface with amandrel.
 12. The method of claim 1, further comprising post-processingthe composite material using compression molding comprising: forming asheet of the composite material; pouring sliced fiberglass on top of thesheet of the composite material; and covering the sheet of the compositematerial and the sliced fiberglass with an additional layer of thecomposite material.
 13. The method of claim 1, further comprisingpost-processing the composite material using injection moldingcomprising: injecting the composite material in a molten state into amold; and extracting a formed product from the mold by cooling thecomposite material within the mold.
 14. The method of claim 1, furthercomprising molding the composite material into one or more shapes usingone of vacuum compression molding, rotational molding, blow molding, orinjection over-molding.
 15. The method of claim 1, wherein the compositematerial includes: between 80 wt % and 90 wt % of the thermoplasticresin; between 0.5 wt % and 15 wt % of the PPgMA; and between 0.1 wt %to 7 wt % of the plurality of carbon particles.
 16. The method of claim1, wherein the plurality of carbon particles has a pore volume ofbetween about 0.05 cc/g and about 1.5 cc/g.
 17. The method of claim 1,wherein the final density of the composite material is between about0.945 g/cc and about 0.97 g/cc.
 18. The method of claim 5, wherein themolding further comprises: preparing a mold using one or more of a handlay-up process or a pray process; and compacting the composite materialusing hand-rollers.